_content/doc/go1.26: add a couple missing crypto release notes

Change-Id: Idba61f8797c73a29117a68363c5d87466a6a6964
Reviewed-on: https://go-review.googlesource.com/c/website/+/745920
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/_content/doc/go1.26.md b/_content/doc/go1.26.md
index b461f43..b8e4427 100644
--- a/_content/doc/go1.26.md
+++ b/_content/doc/go1.26.md
@@ -385,6 +385,8 @@
 
 #### [`crypto/fips140`](/pkg/crypto/fips140/)
 
+[FIPS 140-3 Go Cryptographic Module](/doc/security/fips140) v1.26.0 includes changes made to the `crypto/internal/fips140/...` packages up to this release, and can now be selected with GOFIPS140.
+
 The new [`WithoutEnforcement`](/pkg/crypto/fips140#WithoutEnforcement) and [`Enforced`](/pkg/crypto/fips140#Enforced) functions now allow running
 in `GODEBUG=fips140=only` mode while selectively disabling the strict FIPS 140-3 checks.
 
@@ -396,6 +398,8 @@
 [`DecapsulationKey1024.Encapsulator`](/pkg/crypto/mlkem#DecapsulationKey1024.Encapsulator) methods implement the new
 [`crypto.Decapsulator`](/pkg/crypto#Decapsulator) interface.
 
+Encapsulation and decapsultion operations are now approximately 18% faster.
+
 #### [`crypto/mlkem/mlkemtest`](/pkg/crypto/mlkem/mlkemtest/)
 
 The new [`crypto/mlkem/mlkemtest`](/pkg/crypto/mlkem/mlkemtest) package exposes the [`Encapsulate768`](/pkg/crypto/mlkem/mlkemtest#Encapsulate768) and
@@ -428,6 +432,10 @@
 Unsafe PKCS #1 v1.5 encryption padding (implemented by [`EncryptPKCS1v15`](/pkg/crypto/rsa#EncryptPKCS1v15),
 [`DecryptPKCS1v15`](/pkg/crypto/rsa#DecryptPKCS1v15), and [`DecryptPKCS1v15SessionKey`](/pkg/crypto/rsa#DecryptPKCS1v15SessionKey)) is now deprecated.
 
+#### [`crypto/sha3`](/pkg/crypto/sha3/)
+
+The zero value of [`SHA3`](/pkg/crypto/sha3#SHA3) is now a usable SHA3-256 instance, and the zero value of [`SHAKE`](/pkg/crypto/sha3#SHAKE) is now a usable SHAKE256 instance.
+
 #### [`crypto/subtle`](/pkg/crypto/subtle)
 
 The [`WithDataIndependentTiming`](/pkg/crypto/subtle#WithDataIndependentTiming)